Thanks for the suggestions.
- The script editor has "Go to Deck" / "Go to Card" menu items which don't presently have a keyboard shortcut; adding shortcuts would be very simple and at least get you a two-keystroke path to what you want. Any preferences?
- I'll give a file-filtering hint for read[] some thought, but it might be tricky to make portable; Browsers (notionally) want filters based on MIME types- which often don't exist or aren't well-recognized for binary formats, and at best this information is a vague suggestion that they may ignore entirely. I've observed very inconsistent behavior for both MIME and extension-based filters, especially on mobile browsers.
- I don't see a way of supplying filenames as a result from read[] without breaking its contract, and in turn many existing decks. It also poses some potential portability issues; on mobile browsers, for example, importing an image may allow a user to take a photo from their phone's camera instead of choosing an image from the local filesystem. I can see how this could be useful, but I'm hesitant to make the breaking change.
- Returning an empty array on canceling a read[] of a binary file is consistent with returning an empty image on canceling a read[] of an image. This design hasn't been re-examined since the introduction of nil as a new option for in-band signaling, though. I'll give this some thought, too.